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Comparison of magnetic particles in airborne dust on Mars and in the Harmattan dust from south of Sahara

Comparison of magnetic particles in airborne dust on Mars and in the Harmattan dust from south of Sahara
Aeolian dust ; Aeolian features ; Comparative study ; Ghana ; Mars planet ; Mineralogy
The magnetic properties experiments on the Mars Pathfinder mission indicate that Martian airborne dust is slightly magnetic. For purposes of comparison similar experiments on the magnetic properties of terrestrial airborne dust on the Earth have
been performed at the University of Ghana. The main result of these experiments is that the airborne Harmattan dust in Ghana is substantially less magnetic than the dust suspended in the Martian atmosphere.

Effect of rock fragment eccentricity on eolian deposition of atmospheric dust

Effect of rock fragment eccentricity on eolian deposition of atmospheric dust
Aeolian dust ; Aeolian features ; Belgium ; Experimentation ; Geomorphometry ; Loess ; Wind speed
The aim of this study is to investigate the physical effects of rock fragment eccentricity on the dust deposition mechanism. This was examined in a wind tunnel. All data in this study refer to intial dust deposition (not accumulation), since only
wind velocities below the dust deflation threshold were tested.

Deposition of windblown dust in central Arizona, USA in Lithology and stratigraphy of loess and paleosols.

Deposition of windblown dust in central Arizona, USA in Lithology and stratigraphy of loess and paleosols.
Dust blown from deserts is a common phenomenon in arid and semi-arid areas. Desert dust is often transported hundreds of kilometres and much of the finer material is carried thousands of kilometres. In the Sonoran Desert soils are very susceptible
to deflation and great quantities of dust are transported locally by dust devils. (DLO).

The aeolian dust accumulation curve

The aeolian dust accumulation curve
Aeolian deposit ; Aeolian dust ; Aeolian features ; Belgium ; Concept ; Experimentation ; Flanders ; Leuven ; Model ; Wind erosion ; Wind speed
This article presents a simple physical concept of aeolian dust accumulation, based on the behaviour of the subprocesses of dust deposition and dust erosion. A model is tested in a series of wind tunnel experiments. Some implications of the model

Harmattan dust deposition and particle size in Ghana

Harmattan dust deposition and particle size in Ghana
Aeolian dust ; Aeolian features ; Agropedology ; Arid area ; Ghana ; Grain size distribution ; Loess ; Research technique ; Sampling ; Sediment transport
This paper describes the development of sampling techniques for monitoring the Harmattan dust deposition in Ghana. It compares 3 different methods to trap the Harmattan dust and describes the difference in amount and particle size distribution
of dust trapped in various agroecological zones.

Sediment loads in an Australian dust storm: implications for present and past dust processes

Sediment loads in an Australian dust storm: implications for present and past dust processes
Arid area ; Australia ; Desert ; Dust storm ; Model ; Queensland ; Soil erosion ; Suspended load ; Wind erosion
The purpose of this paper is to quantify the amount of dust moved in a dust storm in Western Queensland in 1987, and to describe the environmental effects (present and past) of dust entrainment, transport and deposition in the Australian region.

Dust deposition and particle size in Mali, West Africa

Dust deposition and particle size in Mali, West Africa
Aeolian dust ; Aeolian features ; Atmospheric circulation ; Grain size distribution ; Mali ; Season ; Soil properties ; Wind
This paper describes dust deposition processes in Mali, West Africa, during April and May 1990, and examines the relative contributions of dusts from local, regional and more distant sources using dust particle size data. The significance
of these results for studies of dust contributions to soils is discussed.

Pathways of dust input to the Chinese Loess Plateau during the last glacial and interglacial periods

Pathways of dust input to the Chinese Loess Plateau during the last glacial and interglacial periods
In this study, 32 loess-paleosol profiles of the last glacial and interglacial periods were measured for magnetic susceptibility in order to investigate the dust transport pathways of dust input to the Loess Plateau. Because sedimentation rates
decrease downwind from the dust source, the spatial distribution of dust sedimentation rates shows that northwest and west winds were the 2 most important agents for transport of dust to the Loess Plateau during the last glacial cycle.

Correlation between rainfall and dust occurrence at Mildura, Australia : the difference between local and source area rainfalls

Correlation between rainfall and dust occurrence at Mildura, Australia : the difference between local and source area rainfalls
Australia ; Climatology ; Correlation ; Drought ; Dust ; Dust storm ; Precipitation ; Victoria ; Wind
The AA. use dust records at Mildura, Australia along with observed wind directions during dust storms and events and both local and regional source area rainfall for the period 1960-1989 to test the adequacy of using local rainfall and to show
the improvement that could be achieved by using regional rainfall in the likely dust source area.

Aeolian dust contributions to soil on the Namoi Valley, northern NSW, Australia

Aeolian dust contributions to soil on the Namoi Valley, northern NSW, Australia
Aeolian dust ; Aeolian features ; Alluvium ; Australia ; Geochemistry ; Grain size distribution ; Mineralogy ; New South Wales ; Pedogenesis ; Soil
The presence of aeolian dust in soil profiles can easily be obscured by pedoturbation , especially in clay soils with vertic properties, such as those of northern New South Wales. To indicate aeolian dust components within soil profiles typical
of the lower Namoi River Valley, the AA. used a range of granulometric, mineralogical and geochemical methods. The AA. also examined contemporary data on dust deposition rates and compared characteristics of present-day dust with the soil materials.

Aeolian deposition of dust over hills : the effect of dust grain size on the deposition pattern

Aeolian deposition of dust over hills : the effect of dust grain size on the deposition pattern
Aeolian dust ; Aeolian features ; Aeolian transport ; Belgium ; Experimentation ; Flemish Brabant ; Grain size distribution ; Impact ; Leuven ; Topography
Wind tunnel experiments were conducted to investigate the effects of topography on the grain size characteristics of aeolian dust deposits. Experiments were performed on 3 isolated hills having various size and aspect ratios. The longitudinal
profile of the median grain diameter was investigated for each hill. The wind tunnel experiments show that the grain size characteristics of aeolian dust deposits are affected by topography.

Nd isotope evidence for dust accretion to a soil chronosequence in Hainan Island

Nd isotope evidence for dust accretion to a soil chronosequence in Hainan Island
Aeolian dust ; Aerosol ; Biogeochemistry ; China ; Geochemistry ; Hainandao ; Isotope analysis ; Soil ; Soil properties
Hainan soils contain a mixture of material derived from in situ weathering of parent material plus atmospheric inputs dominated by continental dust. The AA. use Nd isotope geochemistry to evaluate the impact of continental dust on a chronosequence
of Hainan soils. On the basis of the geomorphic stability sites, the AA. think that the decrease of dust inputs due to climate changes and the loss of dust due to weathering are the dominant loss mechanisms for dust and lead to underestimates of time
-averaged dust deposition rates in the old sites. They calculate long term dust accretion rates to quantify the deposition. The results also underscore the potential for neodymium isotopes to constrain the origin of soils and paleosols.

Addition of aeolian dusts to soils in southeastern Australia : red silty clay trapped in dunes bordering Murrumbidgee River in the Wagga Wagga region

Addition of aeolian dusts to soils in southeastern Australia : red silty clay trapped in dunes bordering Murrumbidgee River in the Wagga Wagga region
Aeolian dust ; Aeolian features ; Australia ; Clay mineral ; Climatic variation ; Dating ; Dune ; Grain size distribution ; New South Wales ; Palaeoclimate ; Quaternary ; Soil ; Soil properties
In southeastern Australia, aeolian dust deposits are very common and have a significant influence on soil properties and soil landscapes. However, the characteristics of the pure dust materials and the rates of dust-fall in the past are unclear
because of the low overall rate of dust deposition and mixing with locally derived sediments. In the Wagga Wagga region, some dunes have functioned as dust traps, and so provide an opportunity for characterising relatively pure dust deposits and evaluating
past dust deposition rates. Results and discussion.

Rainfall, temperature and dust storm anomalies in the African Sahel

Rainfall, temperature and dust storm anomalies in the African Sahel
Africa ; Arid lands ; Atmospheric dynamics ; Climatic anomaly ; Climatology ; Dust storm ; Sahel ; Statistics
Considering the importance of the dust storm phenomenon in the regional and global climatological context, this study sets out to examine the relationship between annual and interannual fluctuations in dust storm frequency and rainfall

Studies on eolian dust in Greece

Studies on eolian dust in Greece
This paper deals with eolian deposits and dust storms in Greece. Statistics on episodes with atmospheric dust are extracted from meteorological data taken at a number of Greek weather stations. In addition eolian dust of probably Saharan origin

Optical depth, size distribution and flux of dust from Owens Lake, California

Optical depth, size distribution and flux of dust from Owens Lake, California
Aeolian dust ; Aeolian features ; Aerosol ; Arid area ; California ; Dust storm ; Grain size distribution ; Lake ; Remote sensing ; United States of America
Projects LODE (Lake Owens Dust Experiments) took place on the anthropogenically desertified playa and surrounding regions of Owens Lake, in east-central California. Optical depth measurements were taken and aerosol samples were obtained during dust
storm activities from 11-25 March 1993 and April 1996. The purpose of this work was to estimate total mass of dust removed during individual dust events. The dust storms were clearly identified by surface observations and satellite as originating

Quantitative estimates of the effect of climate change on dust storm activity in Australia during the Last Glacial Maximum

Quantitative estimates of the effect of climate change on dust storm activity in Australia during the Last Glacial Maximum
Aeolian features ; Aeolian transport ; Australia ; Climatic variation ; Dust storm ; Global change ; Lateglacial ; Quaternary ; Spatial variation
Quantitative estimates are made of the effect of climate change upon dust activity during the Last Glacial Maximum (LGM), which peaked 18,000 years ago, using present-day measurements of the occurence of dust storms recalculated in the light
of information on LGM climatic change. Dust storm seasons were lengthened and dust paths were modified. Estimates based upon climate alone, without considering the increased supplies of sediment to dust source areas during the LGM, however, probably underestimate
LGM dust activity.

External supply of dust in the Taklamakan sand sea, Northwest China, reveals the dust-forming processes of the modern sand sea surface

External supply of dust in the Taklamakan sand sea, Northwest China, reveals the dust-forming processes of the modern sand sea surface
Aeolian dust ; Aeolian features ; Aeolian transport ; Arid area ; China ; Dust storm ; Geochemistry ; Grain size distribution ; Rare earth elements ; Xinjiang
The AA. investigated dust fallout characteristics at a height of 3 m and rare earth element (REE) geochemistry of different landforms in the Taklamakan sand sea, which has frequent dust events. The seasonal fallout and concentrations of PM10
particles and monitoring results of their land surface concentrations show that the Taklamakan sand sea is surrounded by dust sources, and it's an important dust deposit area. The particle size characteristics of dust sediment suggest that the dust-conveying
capacity of the Taklamakan sand sea is much stronger than that of the Gobi and degraded surfaces on the sand sea edge. It is highlighted that the areas surrounding Taklamakan sand sea are the main dust source areas. Taklamakan sand sea is also an important
source of reworked dust.

Gondolatok a porviharok és a klimatikus környezeti folyamatok összefüggéseiről

Aeolian dust ; Atmospheric dynamics ; Climatology ; Dust storm ; Environment ; Land atmosphere interaction ; Temperature
The study presents some key factors influencing the formation, size and frequency of dust storms and describes the connection between temperature and eolian dust deposits. The role of dust storms and atmospheric dust in environmental processes

Mineralogy of dust deposited during the Harmattan season in Ghana

Mineralogy of dust deposited during the Harmattan season in Ghana
Aeolian dust ; Aeolian features ; Aeolian transport ; Africa ; Clay mineral ; Geochemistry ; Ghana ; Mineralogy ; Sahara ; West Africa ; Wind
The AA. studied samples of dust and topsoils in various agroecological zones, from the north to the south of Ghana, focussing mainly on the mineralogy of these materials. Some data about grain sizes and morphology of the samples are also presented
. The relative contents of K-feldspars and plagioclase vary markedly in the different zones. The pH of the dust is significantly higher than that of the local soils, indicating that a substantial amount of the dust comes from the Sahara.

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